feat(strings): add interpolate()

packages/strings/src/index.ts

@@ -4,6 +4,7 @@ export * from "./center";
 export * from "./float";
 export * from "./format";
 export * from "./hollerith";
+export * from "./interpolate";
 export * from "./pad-left";
 export * from "./pad-right";
 export * from "./parse";

packages/strings/src/interpolate.ts

@@ -0,0 +1,20 @@
+const TPL = /\{(\d+)\}/g;
+
+/**
+ * Takes a string template with embedded `{number}` style terms and any
+ * number of args. Replaces numbered terms with their respective args
+ * given.
+ *
+ * @example
+ * ```ts
+ * interpolate("let {0}: {2} = {1};", "a", 42, "number")
+ * // "let a: number = 42;"
+ * ```
+ *
+ * @param src
+ * @param args
+ */
+export const interpolate = (src: string, ...args: any[]) =>
+    args.length > 0
+        ? src.replace(TPL, (m) => String(args[parseInt(m[1], 10)]))
+        : src;